Daniel b



(No Model.)

D. E. KEMPSTER. HAND DRILLING MACHINE.

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C w m J wK l A ml I f V W a H 8 2. m6 w Z w? i UNiTED STATES PATENT Fries.

DAEIEL n. knirrs'rnn, or Bos'ron, MASS, ASSIGNOR TO GEORGE W. snrrn,

OF SAME PLACE, AND BENJAMIN HAND DRIL LI F. SMITH, OF SOMERVILLE, MASS.

NG-MACHINE.

SPECIFICATION forming part of Letters Patent No. 289,110, dated November 27, 1883. Application filed. November 13, 1882. (No model.)

[0 a. whom it may concern:

chines; and I do hereby declare that the same are fully described in the following specification and illustrated in the accompanying drawin s.

%Iy invention relates to that class, of hand drilling-machines commonly called ratchet drills, in which intermittent rotary motion isimparted to the drill-socket spindle by means of the intermittent action of a frictional looking device, which looks the drillspindle and oscillating part together in one direction and dlsengages it in the opposite direction.

The object of my improvements is to pro vide a more simple and efficient locking device, and to produce a hand drilling-machine 'tion of my improvements.

which will be more'useful, noiseless, and durahie, and can be manufactured at less expense; and it consists in the construction herein described and shown.

Figure 1 is a side elevation of my improved hand drilling-machine. Fig. 2 is a sectional Fig. 3 1s a cross-section onview of the same. the line a: m, seenfrom V in Fig. 2. Fig. 4 is a longitudinal section of the frictional lockingroll. Fig. 5 is a sectional view of a modifica- Fig. 6 is a crosssection of the same on the line y 2 seen from U in Fig. 5.

Similar letters of reference indicate like parts wherever they occur in all the figures.

' the forked spindles for thesame.

A isthe drill-spindle, having the drill-socket a and the screw-center c, and provided with cams a a. B is the circular flange, having" lever-socket b and lever b; G, the frictional locking-rolls. cl is the spiral spring, and e The spindle A. has holes e, for the ends of the forked spindles eto enter, thus holding them in position. The spindle A is cored through its center from end to end, thus giving a chance to file out true the socket a, the end opposite being cored smaller to allow for tapping out for the screwcenter a, the screw being made long enough to reach the tapering end of the drill-shank and force it out of the socket cwhen required so to do. The construction of the difierent parts is with a View to using steel or other castings, and is designed, especially, to get the greatest amount of strength with the least amount of weight, and more especially to dispense with labor in making the various parts. Therefore I prefer to make the circular flange B with a strengthening-rib, b, and the inside of the flange 1 form tapering in from opposite sides, smaller at the center, as shown in Fig. 2. This gives a good draft to the pattern, and the castings come clean and smooth, requiring no finishing. cams a may be formed on the spindle A, and the operation will be the same. I prefer to use two cams a a, one on each side of the spindle, as shown in Fig. 3. By so doing 1am enabled, in a two-part flask, to cast the spindles complete, with holes a, requiring no drilling or finishing of the cams. The cams a a, as shown in Figs. 2 and 8, are formed tapering, larger int-he center, to coincide with the circular flangeB, surrounding them. The spindle A has an enlarged portion or collar, the part of of the said collar being finished or turned concentric with the spindle A. A finished ring, a, is fitted to revolve freely on the part a of the spindle A. Dowel-pins b b connect the ring aand the flange B concentrically together. Thus it will be seen that the unfinished working parts of the flange B and spinconcentric with each other by the dowels b b and the ring af, revolving on the part a, as shown in Fig. 2. The rolls 0 are tapered toward the center about the same shape as the space or recess a betweenthe flange B and the cams a, and are placed one in each space, as shown in Fig. 3. The center of therollO is surrounded, when in position, by the forked end of the spindle e, the opposite end of which enters the holes c in the spindle A. Spiral springs d d surround the spindles 6. One end It is obvious that one or more reduced to form a journal, 0, which is partly die A do not touch each other, but are heldof the said springs presses against the spindie A and the opposite end presses against shoulders on the forked spindles. This causes the rolls 0 to be forced into the smaller part of the space 0. A collar, f, held to the spin- (lle A by a set-screw, f, comes up to and in contact with the flange B, covering up the work ing parts and protecting them from dirt, as well as securely holding the several parts together in position. Thelever b is held in the socket b by a set-screw, f and may be quickly removed when required, as is often the case when drilling a hole in a space too small to admit the working of the lever I),- also, in drilling large holes it is often desirable to extend the lever to an unusual length. An adjustable lever is therefore a very great advantage; yet it may be made all in one piece, if so preferred, as heretofore. I

Figs. 5 and 6 show one modification of my improved drill. It is essentially the same as the other, only the cams a a are on the in side ofafiange which is a part of the spindle A. The lever-flange B extends into the cammed spindle and forms a space 0, in which are straight rolls 0, having a journal 0, andpressed up by forked spindles c c, operated by springs d d, as before described.

The operation must be'obvious to all that when the lever b is moved in one direction the frictional contact of the circular flange l3 and spindle-cams a a will grasp 01' wedge the locking-rolls O and securely lock the parts to gether,and thus rotate the drill. hen the motion of the lever b is reversed, the grip be tween the flange B and spindle A is released and the drill remains stationar m Now, owing to the springs (Z pressing the locking-rolls C so closely into the narrowing part of the space or recess 0, the locking together of the parts will instantly take place .on reversing the motion of the. lever 11, thus effectually preventing any lost motion. Of course, a continuous rotary motion of the drill would take place if the 0 cams Ma were double, and two circular flanges with two levers b were used alternately, and

this construction will form a subject for ap plication for patent for treadle motion hereafter.

I also use this device in a bow drilling-machine. The lever 12 and socket b are dispensed with, and two flanges B are used in the form of grooved pulleys, around which the bow-cords are passedin opposite directions, thus pro ducing a continuous rotary motion of the drill forth.

2. The locking-roll G, tapering from opposite ends, smaller in the center, the flange B, tapering from opposite sides on its inner surface to the center, and the spindle-camsa, tapering from opposite sides, larger in the cen-v ter, so that when all are together their con-.

tacting surfaces coincide with each other, as described and set forth.

I11 testimony whereof I have affixed my sig-, nature in presence of two witnesses.

DANIEL E. KEMPSTER.

\Vitn esses:

Gno. A. RICHARDSON, STEPHEN CUSHING. 

